Circuit-interrupter



J. F. TRITLE.

CIRCUIT INTERRUPTER.

APPLICATION FlLD DEC. 15. 1919.

1,398,982. Patented Dec. 6, 1921.

2 SHEETSSHEET I.

Inventor: do n FITPitle, b y 4 His Attovne y.

J. F. TRITLE.

CIRCUIT INTERRUPTER.

APPLICATION FILED DEC. 15, f9l9.

Patented Dec. 6, 1921.

2 SHEETSSHEET 2.

Inventor: John F. Tritle by fl 1, 491% His Attorney.

UNITED STATES PATENT oer-l ce.

JOHN I. TBITLE, OF SCHENEOTADY, NEW YORK, ASSIGNOR TO GENERAL EOEOTRIO COMPANY, A CORPORATION OF NEW YORK. I

OIBCUIT-INTEBBUPTE'B.

' Specification of Letters Patent.

Application filed December 15, 1919. Seriai 110. 845,008.

To all whom it may concern:

Be it known that 1, JOHN F. Tnrrnn, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements in Circuit- Interrupters, of which the following is a specification.

My invention relates to circuit interrupters and it provides improved means whereby the arc formed upon the interruption of an electric circuit is quickl disrupted.

More specifically my lnvention comprises an improved arrangement including amon other features the inventions disclosed an claimed broadly in my prior patents No. 1,323,798, Dec. 2, 1919, and No. 1,323,799 Dec. 2, 1919, and my appl'cation for United States patent, Serial No. 342,326, filed December 2, 1919.

The present invention resides in certain improved features of construction and arrangement which will be explained fully hereinafter and specifically pointed out in the claims.

For a better understanding of my invention, reference is had to the accompanying is an elevation of my improved electromag-.

net switch with certain of the parts in section in order to illustrate its principle of operation; and Fig. 4 is an end view of my improved arc chute. Referring first to Fig? 1, the dynamo electric machine 10 is adapted to be controlled by means of my improved electromagnet switch by controlling the resistance R which is included in the circuit of the d amo electric machine. The switch controlling this resistance R is provided with a pivoted movable contact member 11 which has a relatively small inertia effect. This switch member is provided with a contact 12 which is adapted to make engagement with another contact 13 which is biased toward the contact 12 by means of the spring 14. The contact 13 is relatively quite heavy and has "considerable inertia effect. It is supported in position by means of pins 15 the contacts in closing that the left-hand end of the contact 13 is tilted downwardly and the right-hand end tilted upwardly when the contacts 12and 13 are out of engagement. A wiping action of is thereby provided, and 1t Wlll be observe that by reason of the fact that the contact-13 is cradled in its support, the contacts will aline themselves perfectly. When the contacts close, the resistance R- in circuit with the'dynamo electric machine is short circuited, and when the contacts open, the resistance-is included in the circuit with the dynamo electric machine.- The. relatively li ht, pivoted, movable contact 12 is move into engagement with the contact 13 by means of an operating handle 17 or by means of the electromagnet 18, the winding of which is controlled by means of the pilot switch 19. The arrangement is such that the plunger of the solenoid 18 strikes the lever 20 a blow when the solenoid winding is energized and thereb moves the contact member 11 to the closed position. The contact 11 is retained in its closed position by means of an electromagnet 21 which is provided with a winding 22, the excitation of which is varied by means of a rheostat 23 so as to vary the holding effect of the electromagnet. An armature 24 for the electromagnet 21 is provided on the tromagnet. This conductor 25 is in series With the contact 12 and is provided for automatically releasing the switch member 11 when the current through the contacts 12 and '13 is in excess of a predetermined value. The conductor 25 operates to deflect the flux of the electromagnet 21 from the armature 24 without materiall varying the flux of the electroma et. T us, when an overload occurs, the ux of the electromagnet is shifted to the right of the conductor 25 and awayv from the armature 24, thereby releasing the contact member 11 so as to automatically open the contacts 12 and 13 in accordance with the bias of the contact member 11 to the open position which is produced by the spring 26. en an overload occurs, the

Patented Dec. 6, 1921.

.switch member 11 and a straight conductor 25 1s disposed between. the poles of the elec-'- contact member 11 will move quickly to its open position by reason of havin a small inertia effect, and the contact 13 aving a greater inertia effect will not immediately follow the contact 12, thereby efiecting a very quick opening of the contacts. A series blowout coil disposed at right angles to the plane of movement of the contacts 12 and 13 is provided with a coil 27 on one side of the contacts and a coil 28 on the other side of the contacts. The function of these blowout coils is to cause the arc to proceed from the contacts in the plane of movement of the contacts, so that after the arc is lengthened a slight amount it will come into contact with the auxiliary arcing horns 29 and 30, which are connected to the electric circuit. The are will thereupon leave the contacts 12 and 13 and be established between the auxiliary arcing horns. After the arc has extended a slight amount further, the auxiliary blowout coil 31 is included in the circuit. This blowout coil will set up a flux in a direction transverse to the direction in which the arc lengthens, thereby causing the arc to lengthen as shown in the dotted lines. This blowout is so constructed and disposed with respect to the contacts 12 and 13 that the arc is divided into two parts as shown. Each of these parts, as will be explained later in connection with Fig. 1, is blown out through a narrow arc chute so that each part of the arc will be quickly disrupted.

In Fig. 2 I have shown the manner in which the series blowout coils 27 and 28 are disposed with respect to the switch contacts 12 and 13. It will be seen that these coils are mounted on a laminated magnetic structure 32 in order that a powerful magnetic flux may be set up transverse to the plane of movement of the contacts 12 and 13.

It will be seen that when the switch opens in response to abnormal circuit conditions, the switch contacts immediately separate, and the arc establishedbetween the contacts is forced upwardly by means of the series blowout arrangement comprising coils 27 and 28 mounted in the magnet structure 32; then the arc is established between the auxiliary arcing horns 29 and 30, and later the auxi iary magnetic blowout 31 is included in circuit with the arc to supplement the blowout coils 27 and 28. Byreason of the fact that the resistance of the auxiliary blowout 31 is considerably less than the resistance of the arc between the two arcing tips 33 and 34, a considerable portion of the current of the arc will flow through this auxiliary blowout. A separator 35 of insulating material will effect a separation of the are into two parts as shown, with the auxiliary blowout included in series between the two parts.

Referring to Figs. 3 and 4, wherein similar reference numerals indicate similar parts to those of Figs. 1 and 2, it will be observed that the force which biases the contact member 11 to the open position may be varied by varying the position of the plate 36 to which .the springs are secured with respect to bolt 37. It will also be observed that the compression of the spring 14 may also be varied so as to vary the contact pressure between the contacts 12 and 13. In this figure, the pins 15 and 16 are a part of the contact 13 and these pins slide in slots in the stationary support, instead of the arrangement as shown in Fig. 1.

The are chute 38 of asbestos, hard fiber or the like, is mounted with respect to the switch contacts so that the chute can be swung away from the contacts to permit inspeetlon of the contacts by removing either one of the pins 39 and 40 and swinging the arc chute about the other pin. Thus, the arc chute can be swung either to the right or to the left as the conditions of the installation of the switch may require or as the convenience-of the inspector may dictate. It will be noted that the barrier 41 in the middle of this are chute and the auxiliary blowout coil 31 divide the arc chute into two compartments, so that each part of the arc may be blown out through an arc chute of restricted area, thereby increasing the resistance and cooling effect of the arc and preventing the am from wandering from one side to the other of the arc chute. In that way the effective lines of force of the auxiliary blowout are substantially perpendicular to the path of thecurrent in the arc. Metallic plates 42 and 43 are secured in the arc chutes, and these plates are connected with the core 44 of the auxiliary blowout 31 in order to increase the effectiveness of the auxiliary blowout. v

The pilot switch 45 is provided for opening the switch at will so as to include the resistance R in the circuit of the dynamo electric machine. Opening the pilot switch 45 will denergize the holding coil 22 and also prevent the energization of the actuating coil 18 until the pilot switch 45 is again closed. The line switch 46 is provided for disconnecting the dynamo electric machine and its control from the source of supply.

l/Vhat I claim as new and desire to secure by Letters Patent of the United States,'is,

1. The combination in an electric switch, of a pair of relatively movable cotiperating circult interrupting contacts, the first contact being biased away from the second and having a relatively small moment of inertia, the second contact bein ,biased toward the first and having a relatlvely large moment of inertia, the second contact bein cradled 1n a support so as to permit 0 a longitudinal and tilting movement when the first contact makes engagement therewith, whereby the contacts accurately aline themselves, a wiping action of the contacts is secured, and when the first contact is moved out of engagement with the second contact the the secoiiid contact will not immediately follow rst.

2. The combination in an electric switch, of a pair of relatively movable cooperating circuit interrupting contacts, the first contact being biased away from the second and having a relatively small moment of inertia, the second contact bein biased toward the first and having a relatlvely large moment of inertia, and means for supporting the second'contact, comprising two lost motion connections, one of which permits a longitudinal movement of the contact and the other which causes the contact to be tilted when moved longitudinally, ,whereby the contacts accurately align themselves, a wiping action of the contacts is secured,

' and when the first contact is moved out of engagement with the second contact, the second contact will not immediately follow the first.

3. The combination in an electricv switch, of a pair of relatively movable cooperating circuit interrupting contacts, an arc chute hinged to the support for said contacts so as to be swung away from the contacts in either of two opposite directions in the plane of movement of the contacts, a normally inactive magnetic blowout carried by the arc chute, disposed .in the plane of movement of the contacts, adapted to be included in the circuit with the are formed between the contacts and adapted to divide the are formed between the contacts when the contacts separate, the said chute having two narrow paths for the are through which the parts of the are are caused to lengthen by the action of the blowout.

4. The combination in an electric switch, of a pair of relatively movable cooperating circuit interrupting contacts, a main magnetic blowout comprising a core with a thereon in series with one of the contacts, the said core having an air gap in which the contacts make engagement, an arc chute hinged to the support for said contacts and having two narrow passages in the plane of movement of the contacts, a normally inactive auxiliary blowout coil carried by the arc chute, an arcing horn electrically connected to each contact, where- Y by when the contacts separate the are formed is lengthened by the main magnetic blowout so as to be established between the arcing horns, after which a further lengthening of the arc includes the auxiliary blowout coil in series with the arc and the arc is divided into two parts, each of which JOHN F. TRITLE. 

